Program sequence timer



Jan. 25, 1966 R. PLASKO PROGRAM SEQUENCE TIMER Filed May 1. 1961 FIGZ Ym w TO UK NK 00 S FT 0 W T H H KA R W 4 H m 6m m N m A m F w mom M nf.RI 0 w mm m X E 2 m D m I $4 N w L l HI EW SW W DA US IS 8 UR R0 W0 3ST BP SD.

TIME

'ated fluid valves, and electric switches.

United States Patent 3,231,692 PROGRAM SEQUENCE TIMER Emil R. Plasko,Walled Lake, Mich, assignor to American Radiator & Standard SanitaryCorporation, New York, N .Y., a corporation of Delaware Filed May 1,1961, Ser. No. 106,730 6 Claims. (Cl. 200-36) This invention relates toa program timer, i.e., a device for closing a multiplicity of electricalcircuits in a predetermined or preselected manner so that the circuitsmay be utilized to control the operation of various electrical devicessuch as electric motors, electrically-oper- The invention is applicablefor the control of such devices as automation machinery and homeappliances such as clothes washing machines.

One object of the invention is to provide a program timer which ischaracterized by small size and low manufacturing cost.

A further object of the invention is to provide a timer including anovel assembly of two molded mating case sections, each having specialinternal projections, lugs and guide surfaces formed integrallytherewith to mount the operating components of the timer.

An additional object of the invention is to provide a timer whichincorporates an indexable timer disc characterized by a rapid indexingmotion for thereby breaking contact welds.

A further object of the invention is to provide a timer including anovel low cost arrangement of rotary timer disc and electrical brushassemblies.

A still further object of the invention is to provide a timer whereinthe timer-controlled circuits are automatically unloaded during theindexing stroke of the timer disc so as to prevent arcing across thetimer contacts.

A still further object of the invention is to provide a timer having amaster switch, together with a novel axially shiftable stem foroperating same, said stem having a novel integrally formed detent meansfor retaining it in two positions of adjustment.

Other objects of the invention will be apparent from the followingdescription:

In the drawings:

FIGURE 1 is a sectional view of one embodiment of the invention taken online 11 in FIG. 2;

FIG. 2 is a sectional view taken on line 22 in FIG. 1;

FIG. 3 is a fragmentary sectional view taken on line 3-3 in FIG. 1;

FIG. 4 is a sectional view taken on line, 4-4 in FIG. 1;

FIG. 5 is a sectional view taken on line 55 in FIG. 1; and

FIG. 6 is a chart illustrating a performance characteristic of the FIG.1 embodiment.

Referring more particularly to the drawings, there is shown therein awashing machine timer, including two plastic case sections 10 and 12,said sections being of generally dish-like character with peripheralwall portions thereof having their edges mating with one another tocause the sections to fit one against another. Suitable U-shaped clips(not shown) are preferably provided to lock the two case sectionstogether.

Section 10 comprises a top wall 14, rear wall 16, right end wall 18,left end wall and front wall 22. Case section 12 comprises a bottom wall24, rear wall 26, right side wall 28, left side wall and front wall 32.As best shown in FIG. 2, bottom wall 24 is provided with a downwardlyextending wall portion 34 and a laterally extending wall portion 36,said wall portions forming a well or pocket for receiving theconventional electric ice timer motor 38. The lead-in wires for thismotor are shown at 40.

Motor 38 is provided with an output gear 42 which meshes with a largergear 44, a suitable pin 45 being provided on the motor casing to mountthe larger gear for rotary movement. As shown in FIG. 2, gear 44 isprovided with a projection 46, said projection forming a cam surface 48located eccentrically of the axis of pin 45. As best seen in FIG. 5,projection 46 is in horizontal alignment with a slot 50 formed in theundersurface of slide element 52. By this arrangement, when gear 44 ispowered in the clockwise direction (by motor 38) projection 46 movesinto slot 50 and sequentially strikes the slot surfaces 54 and 56 tothereby cause the slide element 52 to be reciprocated in the arrow 58direction. As shown, surface 54 extends at a large angle to thedirection of slide element travel, and surface 56 extends at acomparatively slight angle to the direction of slide element travel.

The slide element is mounted for back and forth movement on guidesurfaces formed by rectangular blocks 60 and 62 formed integrally withcase bottom wall 24. Sidewise movement of the slide element is preventedby the walls 64 and pins 66, said walls and pins being formed integrallywith the corresponding rectangular blocks for manufacturing economies.Undesired upward displacement of the slide element is prevented by twopins 68 formed integrally with the top wall 14 of case section 10. Itwill be noted that all of the guide surfaces for the slide element areformed at the time the case sections are molded and that no separateinserts or other costly guide mechanisms are required.

The slide element as shown in FIG. 1 is biased against wall 26 by meansof a compression spring 70, which is trained between a seat formed bythe spaced walls 72, and the laterally extending shoulder 74 formedintegrally on the slide element. The slide element is provided with anextension 76 to prevent the spring from buckling or slipping off theslide element.

The slide element is provided with an integrally formed reed-like pawl78 of relatively small lateral thickness, the arrangement being suchthat under certain conditions the pawl is permitted to flex or bend asnecessary to permit movement of the large timer disc 80. The centerportion of this disc is keyed to the non-circular enlarged portion 82 ofthe stem 84 which is mounted for rotary motion in semicylindrical hub 86and cylindrical hub 88 as best shown in FIG. 2. During normal operationof the timer the shaft 84 rotates with the timer disc when it is desiredto temporarily or otherwise interrupt the timer operation a manual pullis exerted on stem 84 to cause same to be shifted axially. During thisaxial shift the timer disc remains in place without axial movement.

Disc 80 is keyed to shaft portion 82, but the shaft does not serve asthe sole support for the disc. Thus, to prevent wobbling of the discaround the shaft axis there are provided six pins 90. Three of thesepins are formed integrally with bottom case wall 24 so as to engage theunderside of disc 80, and the other three pins are formed integrallywith the case top wall 14 so as to engage the upper surface of disc 80.By this arrangement the disc is precluded from wobbling about itsconnection with shaft portion 82.

The periphery of disc 80 is provided with teeth 92 configured to definedriver surfaces 94 and cam surfaces 96. As shown in FIG. 1 disc 80 hasjust been indexed through one increment of its motion, and cam surface48 has not yet reached the slot surface 54 to begin the next movement ofslide element 52. As gear 44 is powered clockwise from its illustratedposition the cam surface 48 J strikes surface 54, and the eccentricityof surface 48 about pin 45 causes the slide element 52 to be slowlyretracted away from case rear wall 26. During this slow retractingmovement pawl '78 is drawn past the cam surface 96, but disc 80 isprevented from substantial rearward motion by the pawl 98 (to bedescribed hereinafter). As cam surface 48 begins to traverse the surface56 the spring 70 causes the slide 52 to move very rapidly toward wall 26so as to index the disc 80 in a clockwise direction. The time duringwhich cam surface 48 engages surface 54 is appreciably longer than thetime during which surface 48 engages surface 56 so that the time periodfor retracting the slide element away from wall 26 is appreciablygreater than the time period required for spring 70 to subsequentlyadvance the slide element toward wall 26. Thus, the index stroke ofslide 52 is rapid and the slide retract stroke is slow as will beobserved from the graph shown in FIG. 6. The slight angle of surface 56to the directional plane 58 prevents impacting of the slide 52 by spring70 and suitably controls its speed.

In line with one of the objects of this invention, pawl 98 is formed andmounted in a simplified manner. Thus, the pawl is formed as a one pieceelement, including a hollow hub portion 97, an upper detent arm portion,and a lower spring arm portion 101. This one piece element is freelymounted by slipping the hub portion over a pin 99 which is formedintegrally with case bottom wall 24. In the installed position of pawl98 spring arm portion 101 engages case wall 26 to resiliently urge thedetent portion against the disc teeth 92.

Referring to FIG. 1, the upper and lower surfaces of disc 80 areprovided with printed electrically conductive track portions 100, saidtrack portions being arranged as arcuate track areas centered about theaxis of shaft 84 so that during rotation of the disc the various printedtrack areas traverse the electrically conductive brush elements denotedby numerals 102. As shown in the illustrative drawing there are elevenbrush elements 102 engaged against the upper surface of disc 80 andtwelve brush elements 102 engaged against the undersurface of disc 80.The nature of the printed tracks 100 will in different instances bevaried according to the natures of the different programs which it isnecessary for the timer to deliver.

In the illustrated embodiment the twelve lower brushes 102 are formed asinserts in a molded block 104, said block having its lower face abuttingagainst the surface of case wall 24 and having its upper face abuttingagainst the downwardly extending portion 106 of the case top wall 14.The undersurface of block 104 is provided with depressions which fitover and around buttons 108 formed integrally with case wall 24, thearrangement being such that black 104 is locked in place when the twocase sections and 12 are secured together, as by the aforementionedU-clips.

As seen in FIG. 1, the right end portions of the lower brushes 102 arelocated within a molded flange portion 110 of the block 104. As shownbest in FIG. 4 the upper face of each brush lies in the plane of theupper surface of flange 110 so that when a female type lead-in connector(not shown) is manually telescoped onto flange 110 the various brushes102 will connect with the conductive portions in the connector to thustake current from and deliver current to various electrical deviceswhich the timer is designed to control. In order to provide access tothe flange 110 the case side wall 28 is cut away, as at 112, to form anopen space into which the aforementioned female connector can beextended.

The upper set of brushes 102 is imbedded in a molded block 104aconstructed generally similarly to block 104, except for its location inthe case. Thus, block 104 is located in the lower area of the caseadjacent its right front corner, whereas block 10411 is located in theupper portion of the case adjacent the rear right corner. Block 104a isprovided with recesses similar to the recesses which receive projections108, the only difference being that in this case the buttons are formedon the top case wall 14 instead of on the lower case wall 24. The moldedblock 104a is retained in place by means of an upwardly extendingportion 106a formed integrally with the case bottom wall 24. Also, anopening similar to opening 112 is provided in rear wall 26 to permitaccess to the flange of block 106a for connecting same with a lead-infemale connector (not shown).

The above described arrangement of blocks I06 and 106a permits a largenumber of brushes to operatively engage the upper and lower surfaces ofthe timer disc so as to permit the disc to operatively control a largenumber of electrical control circuits. In this connection it will beunderstood that both the upper and lower surface of disc are providedwith suitable conductive track portions and that at any one instantcertain of these track portions are engaged with the brushes whileothers are de-energized in accordance with the program of the timer. Theprogram may be changed by merely replacing the timer disc.

During the periods when the conductive track portidns 100 are justcontacting or just leaving the brushes 102 it is desirable that thebrushes be d e-energized so as to prevent arcing across the spa-cesbetween the contacts and the brushes. In order to automaticallyde-energize the brushes during such periods, there is provided anunloading mechanism including a series of surface discontinuities orprojections 114.. In the illustrated embodiment these projections areformed on the underside of disc 80 below the teeth 92, with the terminalpoints or ends of the tracks 1110 being located on imaginary'radiallines just clockwise of imaginary radial lines passing through theleading edges of said projections. With suitable redesign of othercomponents the projections could be replaced by depressions, the termsurface discontinuities being employed to cover both constructions.

As shown in FIG. 4, there is provided a master control switch arm 116formed as an insert in the block 104, said master control arm having arigid upwardly extending operator portion 118 which rides along theundersur-face of disc '80. The left end of arm 116 carries an electricalcontact which registers with a superja-cent contact 120 suitably carriedon a bracket 122. As best shown in FIG. 4, this bracket is of generallyU-shaped character, with a web portion 124 and two leg port-ionsextending downwardly therefrom. One of the leg portions 126 carries acontact which registers with .a contact carried by a leaf spring arm128, the arrangement being such that a conductive circuit is formedthrough arm 116, bracket 122, and leaf spring arm 128.

It will be noted that the above described circuit will be completed aslong as operator 118 rests against the underside of disc 80 and shaft 84is in its illustrated lowered position. Whenever arm 116 leaves contact120 or arm 128 is raised by shaft shoulder 130 the circuit is broken.

During certain of the indexing strokes of disc 80 the operator 118 willbe engaged by one of the projections 114, whereupon the operator and arm116 will be depressed so as to break the engagement with contact 120 andthereby interrupt the master control circuit for brushes 102. The mastercontrol circuit is suitably connected into the circuitry formed by thebrushes 10-2 so that the conductive tracks 100 are de-energized as theymake and break their connections with brushes 102. As will be seen fromFIG. 1, the terminal ends of the tracks 100 are located on radial lineswhich pass through points slightly clockwise of the driver surfaces 94on teeth 92, so that the circuit is broken at 120 just slightly beforethe conductive tracks 100 engage or disengage the brushes 102. Duringthe times of track-brush engagement or disengagement the circuits areunloaded to thus prevent any arcing across the conductive surfaces. Thisrelationship is diagrammatically indicated in FIG. 6, from which it willbe noted that switch arm 116 opens just prior to opening of brush 102.The opening of switch 116 takes place just at the start of the indexstroke as will be evident from FIG. 6. Since the index stroke ischaracterized by a very rapid disc speed (and consequent inertia force)any contact welds at 120 are broken easily.

An illustrative sequence of movements involves a relatively slowretraction of slide 52 away from wall 26, a relatively fast startingmovement of the slide toward wall 26, an opening of the contact at 116,a make and/or break of one or more brushes 102, a closing of the contactat 120, a cessation of the index stroke, and a slow retraction of theslide 52. The projections 114 are preferably provided only on thoseteeth which correspond wit-h the beginnings or ends of the tracks 100;consequently arm 116 is moved to the circuit-unloading position onlyduring the periods of potential arcing.

As previously noted, the circuits for the brushes may also be unloadedby the switch arm 128. This switch arm extends from block 104 past shaft84 into vertical registry with the contact carried by bracket leg 126.The contact of switch arm 128 may be disengaged from the leg 126 contactby upward axial motion of shaft 84. Thus, as shaft 84 is manually pulledupwardly the shoulder 130 thereof strikes switch arm 128 to cause itscontact to leave the contact carried on leg 126, to thus break themaster control circuit for brushes 102. During this upward motion ofshaft 84 the detents 132 on the shaft are moved radially inwardly topermit of their passage through the hub 88. To accommodate this inwardradial movement the shaft is provided with two through slits 134, saidslits serving to make the outer web portions 135 of the shaft stifflyresilient so that during upward shaft movement the detents 132 will snapinwardly and then outwardly to releasably lock the shaft in its upwardposition of adjustment. The shaft is limited in its upward movement byengagement of shoulder 130 with the lower surface of hub 86. The shaftmay be returned downwardly by a deliberate manual push on a knob (notshown) which is secured to shaft 34-. This arrangement of axiallyshiftable shaft and switch arm 128 is generally conventional, thepresent invention being concerned therewith only in the fact that anovel detent structure and case structure is incorporated to simplifythe general arrangement.

In summary, the operation of the timer is initiated by manual depressionof shaft 84 to its illustrated position wherein the master controlcircuit is completed at 120 and 128. The energiZati-on of motor 38causes the gear 42 to begin its continuous rotation, whereupon the gear44 is thereby rotated to cause its cam 48 to traverse the cam surfaces54 and 56. During each traverse of surface 54 the slide 52 is slowlyretracted while pawl 98 holds the disc 80 against counterclockwisemovement. During each subsequent traverse of surface 48 past and beyondcam surface 56 the compression spring 7 0 snaps the slide 52 rapidlytoward wall 26 to thus index the disc 86 rapidly in the clockwisedirection for a distance slightly greater than the distance of a'tooth92. During certain ones of the index strokes projections 114 becomeoperative to unload the conductive tracks 1%, and during such indexstroke-s the conductive tracks make and/or break their connections withthe brushes 1&2 as previously described.

The illustrated embodiment is characterized by extreme parts simplicity,particularly as regards the case construction, slide-disc arrangement,circuit-unloading means 112, brush-block construction at 102 and 104,detent-shaft arrangement at 132 and 84, disc anti-wobble means 90, andpawl-spring arrangement at 8 and 101.

It will be understood that various changes may be resorted to in one ormore of the components without departing from the spirit of theinvention as set forth in the accompanying claims.

I claim:

1. In combination, upper and lower opposed mating case sectionsreleasably secured together to define a case top wall, a case bottomwall, and an enclosed space therebetween; a pair of blocks formedintegrally with the lower case section to define two guide surfaces; aplastic slide element slidably disposed on said guide surfaces formovement parallel to the top and bottom case walls; means for movingsaid slide element, including a gear disposed in the space beneath theslide element, a cam-forming projection extending upwardly from saidgear, and a spring trained between the slide element and one of the caseside walls; -a circular timer disc disposed between the case top andbottom walls in the general plane of the slide element; peripheral teethon the disc; a reed-like pawl formed integrally with the slide elementand operatively engaged with the disc teeth so that during movement ofthe slide element by the spring the disc is indexed rapidly in onedirection; first and second sets of circular printed electricallyconductive tracks formed on the upper and lower faces of the disc; firstbrush means including a molded block disposed adjacent the case topwall, and a series of electrically conductive brushes imbedded in saidblock and engaging the upper face of the disc to deliver current to andremove current from the upper tracks; second brush means including asecond molded block disposed adjacent the case bottom wall and a set ofbrushes imbedded therein and extending into engagement with the lowerface of the disc to deliver current to and remove current from the lowertracks; means for unloading the disc tracks during certain ones of theindex movements, including a switch arm disposed adjacent the peripheryof the disc and a series of projections formed on the disc, wherebyduring disc movement the projections deflect the switch arm to operatesame; and manually operable control means for unloading the disc tracksindependently of the abovementioned unloading means, including anaxially shiftable stem extending through the center of the disc and adeflectable switch blade operated by shifting movement of the stern;said stem having at least one slot adjacent one of its side surfaces todefine a resilient radially movable web, and a detent formed on said webto releasably retain the stem in one of its positions of axialadjustment.

2. In combination, a multiplicity of control circuits; a uni-directionalrotatable program timer element having a cycle of movement forsuccessively opening and closing the multiplicity of circuits; saidcircuits comprising a series of stationary reed-like switch arms, and aseries of printed circuit tracks located on the timer element fortraversing said arms; and means including surface discontinuitiesdirectly on the timer element, and a master switch having an actuatorlocated in the path of the surface discontinuities for automaticallyunloading the circuits during their opening and closing periods.

3. In combination, a rotary timer disc having peripheral teeth thereon;arcuate electrically conductive tracks on at least one face of saiddisc; a brush assembly disposed adjacent said one disc face, said brushassembly including a mounting block and a series of reed-like brushelements extending therefrom into engagement with the adjacent tracks onthe disc face; a slide element mounted for rectilinear movement in aplane parallel to the disc plane; a pawl carried by the slide elementand engaged with the disc teeth so that movement of the slide element inone direction causes the pawl to advanceably index the disc by pressureon a disc tooth, and movement of the slide element in the reversedirection causes the pawl to reset itself for engagement with asucceeding disc tooth; a rotary cam disposed adjacent the slide elementfor pressure engagement therewith; cam-engageable follower surfaces onthe slide element arranged so that during a portion of the cam movementthe slide element is moved relatively slowly in the aforementionedreverse direction; and spring means arranged to be loaded by movement ofthe slide element in the reverse direction so that when thepawl-resetting movement is completed the spring means is effective torapidly advance the slide element and pawl in the disc-indexingdirection.

4. In a program timer: a case including two parallel case walls; arotary timer disc disposed between said walls; an axially shifta'blecircuit-unloader stem slidably keyed to the center portion of said discto normally rotate therewith during its period of rotation; and meansfor supporting the disc against w-obbling, including at least threepinlike project-ions extending from each of the aforementioned casewalls into engagement with the adjacent face of the disc at pointsspaced inwardly of the disc periphery.

5. In a program timer: a case including two relatively closely spacedparallel case walls; a rotary indexable disc disposed between said wallsand parallel thereto; a set of printed circuits on at least one face ofsaid disc; and at least .one brush assembly mounted between said Wallsso that said one set of circuits is engaged by a set of brushes; saidone brush assembly comprising a mounting block and reed-like switchelements extending therefrom into engagement with said one disc face,said mounting block having a relatively thin plug-on portion adapted toreceive a plug type connector and a relatively thick anchoring portioncontiguous with the two case walls.

6. In a program timer: a case including two relatively closely spacedparallel case walls; a rotary indexable disc disposed between said wallsand parallel thereto; a set of printed circuits on each face of saiddisc; and brush assemblies mounted between said walls so that each setof circuits is engaged by a set of brushes; each brush assemblycomprising a mounting block and reed-like switch elements extendingtherefrom into engagement with the disc surface, each mounting blockhaving a relatively thin plug-on portion adapted to receive a plug typeconnector and a relatively thick anchoring portion contiguous with thetwo case walls.

References Cited by the Examiner UNITED STATES PATENTS 1,529,220 3/ 1925Schroeder 200146 X 1,622,027 3/ 1927 Couchman et al 7'4-'125 1,738,44412/ 1929 Nagem 20024 2,257,537 9/1941 Sarnburg 20037 2,532,627 112/1950K-oci 20037 2,710,623 6/ 1955 Andrews 200166 2,736,204 2/1956 Hill 741252,877,317 3/1959 Euler et al. 200-38 3,028,458 4/1962 Stnathearn et al.20038 3,053,947 9/1962 Bowman et al. 200-38 KATHLEEN H. CLAFFY, PrimaryExaminer.

WALTER STOLWEIN, BERNARD A. GILHEANY,

ROBERT K. SCHAEFER, Examiners.

1. IN COMBINATION, UPPER AND LOWER OPPOSED MATING CASE SECTIONSRELEASABLY SECURED TOGETHER TO DEFINE A CASE TOP WALL, A CASE BOTTOMWALL, AND AN ENCLOSED SPACE THEREBETWEEN; A PAIR OF BLOCKS FORMEDINTEGRALLY WITH THE LOWER CASE SECTION TO DEFINE TWO GUIDE SURFACE; APLASTIC SLIDE ELEMENT SLIDABLY DISPOSED ON SAID GUIDE SURFACES FORMOVEMENT PARALLEL TO THE TOP AND BOTTOM CASE WALLS; MEANS FOR MOVINGSAID SLIDE ELEMENT, INCLUDING A GEAR DISPOSED IN THE SPACE BENEATH THESLIDE ELEMENT, A CAM-FORMING PROJECTION EXTENDING UPWARDLY FROM SAIDGEAR, AND A SPRING TRAINED BETWEEN THE SLIDE ELEMENT AND ONE OF THE CASESIDE WALLS; A CIRCULAR TIMER DISC DISPOSED BETWEEN THE CASE TOP ANDBOTTOM WALLS IN THE GENERAL PLANE OFTHE SLIDE ELEMENT; PERIPHERAL TEETHON THE DISC; A REED-LIKE PAWL FORMED INTEGRALLY WITH THE SLIDE ELEMENTAND OPERATIVELY ENGAGED WITH THE DISC TEETH SO THAT DURING MOVEMENT OFTHE SLIDE ELEMENT BY THE SPRING THE DISC IS INDEXED RAPIDLY IN ONEDIRECTION; FIRST AND SECOND SETS OF CIRCULAR PRINTED ELECTRICALLYCONDUCTIVE TRACKS FORMED ON THE UPPER AND LOWER FACES OF THE DISC; FIRSTBRUSH MEANS INCLUDING A MOLDED BLOCK DISPOSED ADJACENT THE CASE TOPWALL, AND A SERIES OF ELECTRICALLY CONDUCTIVE BRUSHES IMBEDDED IN SAIDBLOCK AND